1. Technical Field of the Invention
The present invention relates to a method for manufacturing a printed wiring board, the method including an etching step.
For those designated countries which permit the incorporation by reference, the contents described and/or illustrated in the documents relevant to Patent Application No. 2010-065908 filed with Japan Patent Office on Mar. 23, 2010 will be incorporated herein by reference, as a part of the description and/or drawings of the present application.
2. Description of the Related Art
In continuous manufacturing steps according to reel-to-reel (R-R) method, an etching step for forming wiring patterns is followed by a terminal plating process step, a finishing step and cutting step, which are continuously performed. In addition, after completing all these steps, inspections are performed for wiring widths of completed printed wiring boards.
As an approach for this kind of inspecting wiring widths, known in the art is an approach in which wiring patterns are exposed to laser light and electromagnetic wave, and widths of base portions of wiring patterns (boundaries between copper foils and base material) are measured from the reflected light and fluorescence X-ray light (Patent Document 1: Japanese examined Patent Publication No. H7-104138).
Line widths of wiring patterns formed with printed wiring boards are affected by etching process, and therefore, if any abnormality is detected in line widths, then it is contemplated whether the etching conditions at the moment are appropriate or not, and necessary changes are made to the etching conditions for subsequent execution.